Tuning coil for wireless receiving sets



Sept. 1, 1925. 1552,124

' E. DIAZ TUNING COIL FOR WIRELESS RECEIVING SETS Filed Dec. 1 1924 FlG.3.

Ll l l l i Patented Sept. 1, 1925.

' UNITED STATES PATENT 3 mm ESPERANZA DIAZ, 0F MEXICO CITY, MEXICO, ASSIGNOR 'IO EMILIO JUAN KAI, AND JESUS ANGURES.

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Application men December 18, 1924. serial No. 756,068.

' l To all whom it may concern:

Be it known that L Esrmerrza citizen of the United States of Mexico, residing at the city of Mexico, Mex1co,'have invented certain new and useful Improvements in Tuning Coils for Wireless Receiving Sets, of which the following is a specification.

This invention relates to new and useful improvements in tuning coils for wireless receiving sets;

The primary object of th1s invention is to prov1de a tuning coil having novel means for varying the inductance of the same A further object-of the invention is to provide novel means for cutting in or out the various turns of an induction w1nd1ng.

A still further object of the invention is to provide a tuning coil of the above noted type which is of exceedingly-simple construction, and one that will maintain its high degree of efficiency for a considerable .length of time. M

Other objects and advantages of the mvention will be ap arent during the course of the following escription.

In the accompanying. drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same--- Figure 1 is a side elevational view of the tuning coil embodying this invention,

Figure 2 is a horizontal longitudinal sectional view of the device shown in Fig. 1,

Figure 3 is a vertical sectional view taken upon line III- II of Fig. 1,

Figure 4: is a diagrammatical view of the tuning coil embodying this invention properly connected in a Reinartz receiving cirouit, and v Figure 5 is a detail perspective view of a number of turns of the tunin coil winding and indicates the points at wfii made with the said turns.

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of this invention, the numeral 5 designates a substantially U-shaped frame or support having bearings 6 and 7 formed in the end portions of the same.

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ch contact is The bearing 6 has rotatabl therein a sleeve'7 which rotatab y supports within its bore a tubular shaft 8 havlng shaft 9 rotatably received within its bore. The end 10 of the shaft 9 is journaled in the bearing? of the frame or support 5'.

' Suitably secured to the shaft 9, between the arms of the U-shaped frame or sup ort 5 are a lurality of cross arms 11 which connect t e cylinder 12 to the said shaft. This cylinder 12 has a plurality of inte grally formed, circumferentially extending flanges 13 formed thereon and between which are wound the turns of the primary and secondary windings 14 and 15 of the tuning coil. The primary winding 14: is provided with the leads and b while the secondary winding 15 is provided mounted M5 L4 PAR,

with the leads o and dwhich extend thru suitable openings formed in the cylinder 12.for prqectinginto the bore of the said c linder.

The c lin er 12 has formed integrally therewit or suitably secured thereto the spirally extending rib 16 which underlies the turns of the'secondary winding 15, in the manner illustrated in Figs. 3 and 5, for raising the overlying portions of the said turns, which overlying portions are to be scraped for exposing the conducting portions 17 of the insulated wire forming the winding.

The cylinder 12 is further provided with a pair ofspirally extending ribs 18 and 19 which underlie the turns of the primary windings 14 and function in the same manner as the rib 16 underlying the secondary winding 15, it being understood that the turns of the primary winding 14 are to be scraped to expose t e conducting portions of the wire forming this winding in the same manner as shown in Fig. 5 in connection with the secondary winding.

The arm of the U-sha ed frame or support 5 which has the bearing 7 formed therein is provided with a stationary contact arm 2Ov which is insulated from the frame or support by the bushing 21. This stationary contact arm 20 is preferably formed of round stock and is positioned to I engage the uninsulated or exposed portions 17 of the secondary winding 15 for variably connecting the sa1d turns of the winding with the lead-oil wire22 attached to the suported end of this arm 20. A resilient mem- Ber 23 is provided for maintaining the arm 20 in contact with the turns of the winding 15, it being understood that this resllient member 23 ,may be insulated from the arm 20 or the frame or support 5 in an suitable manner for preventing the same om electrically connec the members 5 and 20. The cylinder 12 1s to'be rotated ligmeaus of the knob 24, secured to the sha 9, for causing relative movement between the exposed portions of the secondary wmdmg 15 and the stationary contact arm 20 for outti in or out thenumber of turns of the sa'i windin Movement of the cylinder 12 is limiter? by the stops 25 which engage the arm 20.

The tubularshaft 8 has a knob 26 attached thereto at the end adjacent the knob 24 and has a laterally projecting arm 27 secured to its remaining end. This arm 27 has connected to its free end a movable contact arm 28 which is insulated by the bushing 29 and is connected to the lead-off wire 30. This movable contact arm 28 is intended be adjusted in respect to the exposed or uninsulated portions of the primary win 14 which overlie the spiral rib 18. The resi 'ent member 31, similar to the member 23, is employed for maintaining the movable contact arm 28 in engagement with the winding 14. Thisarm281stobemovedinrespecttothe winding 14 by the knob 26 and is to be limited in its movement in respect to the winding 14 by the stops 32, carried by the cylinder 12. i

The sleeve 7 has mounted on one end thereof the knob 33 by means of which the sleeve may be rotated. The remaining end of this sleeve has connected thereto the arm 34 which carries the movable contact arm 35 at its outer end. This contactarm 35 is insulated from the arm 34 by the bushing '36 and is connected to the lead-off wire 37, as shown. A resilient member 38, similar to the member 23, is employed for maintaining the movable contact arm 35 in engagement with the exposed or uninsulated portions oi the primary winding 14 which overlie the rib 19. The contact arm 35 is limited in its movement in respect to the winding 14 by the stops 39 which are carried by the cylinder 12.

It will now be seen that by rotating the knob 25, the entire cylinder 12 with the windin 14 and'15 will be rotated in respect to the rame or su port 5. This rotation of the cylinder 12 will cause the spirally arranged exposed portions of the secondary winding 15 to move relative to the stationary contact arm 20 for causin the arm 20 to contact or be connected to 'fierent turns of this winding, thereby varying the inductance of the secondary coil. B operating the knobs 26 and 33, the movab e contact arm 28 and 35 respectively may be shifted in respect to the turns of the primer winding 14 for varying the inductance of t e same.

In Fig. 4 there is shown a diagrammatical view of a Reinartz circuit with the tuning coil embodying this invention properly connected therein. It is not believed necessary to s ifically describe the circuit illustrated or t e manner of connecting the various tuning coil terminals thereto for this tuning coil is not limited in its use to this particular type of winding nor the particular manner of connecting the coils to the type of circuit illustrated.

It is now believed that the method of con structing and the manner of operating this tuning coil will be understood from the above detail description. It is further to be understood that the form of this invention herewith shown and described is to be taken as a preferred example of the same,

and that various changes in the shape, size,

claim 1. In a tunin coil'of the ty described, der, means or rotatably a support,'a cy mounting the cylinder on said su port, a pair of windings on said cylind r, each windin having a spirally extending line of uninsu ated places, means for raising the uninsulated places above the remainder of said windings, a stationary contact arm carried by said support and traversing one windin in engagement with its line of uninsulate places, a contact arm carried by said support and traversin the other windin in engagement with its eof uninsulated places, said last mentioned contact arm bein concentrically movable around said cylin er, means for rotating said cylinder to cause the stationary contact arm to engage successive uninsulated places in its associated winding and means for moving the second mentioned contact arm for causing it to engage successive uninsulated places in its associated winding.

2. In a tuning coil of the ty e described, a support, a cylinder, means or rotatably mounting the cylinder on said support, a pair of windings on said cylinder, each winding having a spirally extending line of uninsulated places, ribs for raising the uninsulated places above the remainder of said windings, a stationary contact arm carried by said support and traversing one windin in engagement with its line of uninsula places, a contact arm carried by said support and traversing the other winding in en'- gagement with its line of uninsulated places, contact arm for causing it to engage successaid last mentioned contact arm being consive uninsulated places in its associated centrically movable around said cylinder,- a winding. knob for rotating said cylinder to cause the In testimony whereof I hereunto affix my stationary contact arm to engage successive signature.

uninsulatedfplaoes in its associated winding,

and a knob or moving the second mentioned ESPERANZA DIAZ. 

